Intel 80386EX

An Intel i386 EX embedded processor inside a Garmin GPS III+

The Intel i386EX (80386EX) is a variant of the Intel 386 microprocessor designed for embedded systems. Introduced in August 1994 and was successful in the market, being used aboard several orbiting satellites and microsatellites.

Intel's previous x86 CPU for the embedded market was the Intel 80186. Like the 80186, the 80386EX integrates several peripherals including a timer, DMA controller, and interrupt controller. This vastly reduces the number of system components required for implementing a 80386EX-based system. Unlike the 80186, the peripherals of the 80386EX are compatible with standard PC/AT components.

Intel did not manufacture another integrated x86 processor until 2007, when it confirmed the Enhanced Pentium M-based Tolapai (EP80579). ^[1]

Characteristics

• Introduced August 1994
• Variant of 80386SX intended for embedded systems
• 26-bit memory addressing for up to 64 MiB of DRAM
• 16-bit data bus, limiting performance but reducing system cost
• Static core, i.e. may run as slowly (and thus, power efficiently) as desired, down to full halt
• Support for System Management Mode ^[2]
• On-chip peripherals:
  • clock and power management
  • timers/counters
  • watchdog timer
  • serial I/O units (synchronous and asynchronous) and parallel I/O
  • DMA
  • RAM refresh
  • JTAG test logic
• Significantly more successful than the 80376
• Used aboard several orbiting satellites and microsatellites
• Used in NASA's FlightLinux project
• Used in USRobotics Courier I modem V.everything (Internal ISA and External RS232 ISDN Terminal Adapters with 56KBPS analog remote access server).
• Used in Ericsson R290 and Globalstar/Qualcomm GSP-1600 satellite phone. ^[3]
• Used in many older Garmin GPS units, such as the GPS 48, II, III, and 12. ^{[4] [5]}
• Used in Akai S5000 & S6000 digital samplers.
• Used in Nokia 9000 Communicator phone. ^{[6] [7]}
• Used in Swarco ITC-2 traffic light controller.
• Used in Sperry Marine Navigat X MKI/MKII gyro compasses.
• Used in Gallagher/Cardax FT 3000
• Used in Videokê/intermagic karaokês

See also

• Intel 80186/Intel 80188
• Intel 80376
• Intel Timna
• Atom (system on chip)
• Intel Quark

References

1. "Intel confirms details of Tolapai, a SoC embedded processor". 30 August 2007.
2. 80386EX Embedded Microprocessor User's Manual (PDF). Intel Corporation. February 1995. Retrieved 2025-11-04.
3. EEVblog #721 - Globalstar Satellite Phone Teardown, 4 March 2015, archived from the original on 2021-12-21, retrieved 2021-09-05
4. "Don't Trash that Old Garmin 48 GPS!". 13 April 2010.
5. http://www.n7cfo.com/vhf/GPS.pdf ^{[ bare URL PDF ]}
6. "Nokia 9000 Communicator - Mobilecollectors.net".
7. https://www.mobilecollectors.net/files_large/img_7028_jpg_large.jpg ^{[ bare URL image file ]}

External links

• 386EX characteristics